This invention relates to novel benzopyran compounds and their pharmaceutically acceptable salts which possess remarkable and durable antihypertensive actions, coronary vasodilating actions and relaxant actions on vascular smooth muscles and the other smooth muscles and pharmaceutical uses thereof.
In U.S. Pat. No. 4,446,113, there is disclosed 6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-(2-oxo-1-pyrrolidinyl)-2H-1-benzo pyran-3-ol(BRL-34915). In European Patent Publication (Laid-open) Gazzette No. 273262/1988, British Patent Publication Gazzette No. 2204868/1988 and European Patent Publication (Laid-open) Gazzette No. 296975/1988, there are disclosed a group of 4-substituted benzopyran compounds having antihypertensive actions, smooth muscle-relaxant actions and the like.